From Longman Dictionary of Contemporary Englishpontoonpon‧toon /pɒnˈtuːn $ pɑːn-/ noun1[countable]TEC one of several metalcontainers or boats that are fastened together to support a floatingbridge2[countable]TT one of two hollow metal containers fastened to the bottom of a plane so that it can come down onto water and float3[uncountable] British EnglishDGC a card game, usually played for moneysyn blackjack American English